Meaning of density (what is it, concept and definition)

What is Density:

Density is a scalar quantity that allows you to measure the amount of mass in a given volume of a substance. The word as such comes from the Latin densĭtas , densitātis .

In the area of ​​physics and chemistry, the density of a material, be it liquid, chemical or gaseous, is the relationship between its mass and volume; it is designated by the Greek letter rho "ρ".

The formula to calculate the density of an object is: ρ = m / v, that is: density is equal to mass between volume. From which, furthermore, we can deduce that the density is inversely proportional to the volume: the smaller the volume occupied by a given mass, the greater the density.

Density is one of the physical properties of matter, and it can be observed in substances in their different states: solid, liquid and gaseous.

According to the International System of Units, the units to represent the density are as follows:

• Kilograms per cubic meter (kg / m ³), grams per cubic centimeter (g / cm ³), Kilograms per cubic decimeter (kg / dm ³) grams per cubic decimeter (g / dm ³) for gases.

Thus, for example, the density of water is 1 g / cm ³, that is, less than that of lead, which is 11.35 g / cm ³.

On the other hand, as density we also refer to the quality of dense, in which case it is synonymous with bushy, solid. For example: "They crossed the dense jungle."

Density allows us to calculate not only the amount of matter in a certain space, but also the number of individuals, which is called demographic density.

Density types

Absolute density

Absolute density is an intensive quantity of matter; It is used to express the relationship between the mass and volume of a substance. It is usually formulated in kg / m ³.

Relative density

Relative density is called that between a substance in relation to another substance that is taken as a reference. Generally used as reference density is that of water at a pressure of one atmosphere at 4 ° C, under which conditions the density of water is 1000 kg / m ³.

Apparent density

The apparent density is that presented by materials that are made up of heterogeneous materials. An example of this would be the soil, which is made up of various substances and contains air gaps inside. Therefore, its total density is actually lower than if it were compact.

Medium density

The average density is that calculated for a heterogeneous system. To obtain the average density, divide the mass of the object by its volume.

Spot density

Point density is used to calculate the density in heterogeneous systems that have a different density depending on the point, position or portion of a substance.

Population density

Population density or demographic density is called the number of individuals who, per unit area, live in a given place. Although the population density does not accurately reflect reality, it is used as a relative meter, hence it is also called relative population.

Population density is expressed in individuals per square kilometer (km ²). Rural areas tend to have a lower population density than urban areas. Some of the most densely populated cities in the world are Macao, in China, Singapore, Hong Kong, and Monaco.

Demographic density is calculated in order to find a balance between existing resources and the use of these by the inhabitants.